In the prior art, a plurality of hand-held devices have been proposed for removal of body tissue during surgical procedures. One particular surgical device includes an ultrasonically driven surgical tool which includes both irrigation fluid supply as well as a source of vacuum for aspiration. Typically, these devices have the irrigation fluid supply tube configured in close proximity to the surgical tip assembly, thereby interfering with easy maneuvering of the handpiece during surgery. U.S. Pat. Nos. 4,753,234 to Martinez and 4,861,332 to Parisi show surgical cutting instruments having these types of irrigation fluid tube configurations.
Other prior art devices have been proposed wherein the surgical handpieces include a proximal end cap which introduces or provides access therethrough for means to operate the surgical handpiece. U.S. Pat. No. 4,577,629 to Martinez discloses a surgical cutting instrument for use in ophthalmic surgery which includes a rear plug. The rear plug has a first bore to permit aspiration of cut material and a second bore for supplying air pressure to the cutting mechanism within the instrument. U.S. Pat. No. 4,316,465 to Dotson, Jr. discloses an ophthalmic handpiece which includes a needle having coaxially irrigation and aspiration passageways. The handpiece also includes a rear plug having tubing connectors therein for connection with an irrigation fluid source and a source of aspiration or vacuum. Neither of these patents disclosing surgical cutting instruments having end caps or plugs therewith teach or fairly suggest all of the features of the present invention including an ultrasonic handpiece having an inner and outer shell and sealing end cap therewith.
U.S. Pat. No. 4,804,364 to Dieras et al. discloses another ultrasound apparatus intended for the curettage of biological tissue using ultrasonic vibrations. In this device, and in an effort to improve upon prior art devices that include suction and irrigation conduits which greatly exaggerate the diameter of a surgical handpiece, a connector block is provided at the proximal end of the handpiece which includes an irrigation tube therethrough as well as a connector connected to a source of vacuum.
However, a need has developed to provide improved ultrasonic handpieces which are uniformly sized to permit ease of handling, include features that facilitate assembly or disassembly of the handpiece, provide separation between electronics and fluids and simplify the overall surgical handpiece design.
In response to this need, an ultrasonic surgical handpiece has been developed which includes a outer shell, inner shell, an ultrasound horn assembly within the inner shell and a sealing end cap to facilitate connection to a source of irrigation fluid, electrical power and a source of aspiration.
None of the prior art mentioned above teaches or fairly suggest all of the features of the present invention including the combination of inner and outer shells, ultrasound horn assembly and sealing end cap.